This invention relates to a transportation device or vehicle. More particularly, this invention relates to a transportation vehicle of the hovercraft type.
Vehicles are known wherein the body of the vehicle is spaced from an underlying surface by a cushion of pressurized air. The air cushion is maintained in part by a downwardly depending skirt usually made of a flexible rubber material. Known hovercraft are not capable of climbing stairways.
An object of the present invention is to provide a hovercraft type vehicle.
Another object of the present invention is to provide a hovercraft type vehicle which is capable of traveling over uneven terrain or floor surfaces.
A further object of the present invention is to provide a hover-type transport method.
A more specific object of the present invention is to provide a hovercraft-type apparatus and/or an associated method wherein a load is transported up a multiple-step stairway.
These and other objects of the present invention will be apparent from the drawings and descriptions hereof. It is to be noted that each object of the present invention is attained by at least one embodiment of the present invention. No embodiment necessarily meets every object of the invention.
A personal transportation apparatus comprises, in accordance with the present invention, a frame defining a surface for supporting a load, and a plurality of air-cushion cells mounted to the frame and depending from a lower side thereof, the air-cushion cells each having a changeable height to accommodate variations in an underlying terrain during a translation of the frame over the terrain. The apparatus also comprises a pressure source mounted to the frame and operatively connected to the air-cushion cells for supplying air under pressure to the cells, thereby generating an air-cushion support for the frame. An elevation mechanism is mounted to the frame for lifting the frame from one step to a next higher step of a stairway so that the frame ascends the stairway from a lowermost step to an uppermost step of the stairway.
In at least one embodiment of the invention, the elevation mechanism is separate from the air-cushion cells. More particularly, the elevation mechanism includes a plurality of mechanical parts different from components of the air-cushion cells. For example, the elevation mechanism may include at least two extensible leg members mounted to the lower side of the frame. The leg members may be pivotably mounted to the lower side of the frame.
Pursuant to another feature of the present invention, the elevation mechanism includes at least one drive operatively connected to the leg members for extending the leg members to lift the frame from the one step to the next higher step. Sensors are provided on the frame for monitoring a distance of the frame from an underlying surface, while a control unit is operatively connected to the sensors and the drive for operating the drive in response to detection of the step by the sensors. The sensors may specifically include a plurality of ultrasonic sensors. In that case, the elevation mechanism further includes an ultrasonic signal generator mounted to the frame for producing an airborne ultrasonic wave and directing the wave towards the underlying surface.
The drive may include a linear drive for alternately lengthening and shortening the leg members and a rotary drive for periodically pivoting the leg members during a stairway climbing process.
Where the extensible leg members are a first pair of leg members, the elevation mechanism includes at least one second pair of extensible leg members mounted to the frame on the lower side thereof, for supporting the frame on the next higher step upon a lifting of the frame by the first pair of leg members from the one step to a position over the next higher step.
In accordance with another feature of the present invention, the air-cushion cells include respective rigid telescoping tubes extendible to varying distances from the lower side of the frame, while the elevation mechanism includes a drive operatively connected to the tubes for alternately extending and retracting the tubes. The tubes are each provided at a lower end with a resilient skirt serving as a flexible seal member.
Optionally, the elevation mechanism includes a pneumatic drive, the pressure source being operatively connected to the drive for operating same.
A personal transportation method comprises, in accordance with the present invention, providing a vehicle having a support surface, placing a load on the support surface, thereafter generating an air cushion between the vehicle and an underlying surface, and exerting a motive force on the vehicle during air cushion generation to move the vehicle generally horizontally over the underlying surface towards a lowermost step of a multiple-step stairway. Upon reaching the lowermost step by the vehicle, an elevation mechanism on the vehicle is operated to lift the vehicle step by step from the lowermost step to an uppermost step of the stairway. Thereafter, the air cushion is again generated between the vehicle and a floor surface extending from the uppermost step, during which time another motive force is exerted on the vehicle to move the vehicle generally horizontally over the floor surface and away from the stairway.
In accordance with further aspects of the present invention, the generating of the air cushion both at the bottom and the top of the stairway includes feeding air under pressure to a plurality of air-cushion cells on a lower side of the vehicle, heights of the air-cushion cells being changed during the lifting of the vehicle up the stairway.
The operating of the elevation mechanism may include alternately extending and collapsing and periodically pivoting at least two extensible leg members mounted to the lower side of the vehicle. More specifically, where the air-cushion cells include respective rigid telescoping tubes extendible to varying distances from the lower side of the frame, the operating of the elevation mechanism includes alternately extending and retracting the tubes.
Pursuant to a further feature of the present invention, the method further comprises automatically monitoring distances of the vehicle from the underlying surface and surfaces of the stairway and operating the elevation mechanism in response to detection of the lowermost step.
A hovercraft type vehicle in accordance with the present invention travels over ground and floor surfaces and ascends stairways. The apparatus is capable of ascending conventional stairways with steps each having a width less than approximately eighteen inches or forty-six centimeters, the width being measured along a dimension extending perpendicularly between a leading edge of the respective step and an adjacent higher step.